That's because they don't WANT to understand it.

I blame the schools.

"No, Johnny, you're NOT a special snowflake. You're not very smart. Calling you dumb as a post would be an insult to every sapling with visions of growing up, getting cut down, sawn into lumber, pressure treated with carcinogenic chemicals, and then used as a post! You're going to marry a nagging harpy who sleeps around on you. You're going to have 5 kids who all hate you. You're going to spend most of your adult life slaving away at a job you hate, working for a series of bosses who you wouldn't piss on if they were on fire. You're going to die totally broke of a paralyzing stroke at 58 all alone in a hospital! So no, you DO NOT get to expect a local store owner is going to spend hours and hours of his time working with several multimillion dollar companies trying to get you the SOOOPER SPECIAL bike you think you deserve, because you are NOT worth the $50 that he'd make doing that."